Domain 4: Communicatins and Network Security Flashcards
Simplex
Half-Duplex
Full Duplex
Simplex: One way, like a car radio
Half-Duplex: sends or receives one at a time
Full Duplex: sends and receives simultaneously
Baseband
Broadband
Baseband
- One channel. Can only receive one signal at a time.
- Ethernet networks
Broadband
- Multiple channels
- Can send and receive multiple signals
- Cable TV
PAN
GAN
PAN: Personal Area Network:
- Low power wireless technologies
- Bluetooth
GAN: Global Area Networks
-A collection of WANs
Packet Switched Network
- Data is broken into packets and each sent individually
- Chooses the best route/different route
- Reassembled by receiving node
- Missing packets can be resubmitted
- Out of order packets can be re-sequenced
- Makes unused bandwidth available for other connections
OSI Model Layers - Functions
- Application - Network process to applications
- Presentation - Data Representation
- Session - Interhost Communication
- Transport - End-to-End Connections
- Network - Address and Best Path
- Data Link - Access to Media
- Physical - Binary transmission
OSI Model Benefits
- Reduces complexity
- Standardizes interfaces
- Facilitates modular interfaces
- Ensures interoperability
- Accelerates evolution
- Simplifies teaching and learning
Layer 1: Physical Layer
- Describes units of data as bits represented by energy.
- Cabling
- Devices- hubs and repeaters
OSI Model Layers - Packages
- Application - protocol data units
- Presentation - protocol data units
- Session - protocol data units
- Transport - segment (TCP)/Datagram (UDP)
- Network - packets
- Data Link - frames
- Physical - bits
Layer 2: Data Link
-Handles access to the physical layer as well as local area network communications
-Divided into two sub-layers
>Media Access Control (MAC) - transfers to and from the the physical layer - touches layer 1
>Logical Link Control (LLC) - handles LAN Communications - Touches Layer 3
Layer 3: Network
- Describes routing: moving data from a system on one LAN to a system on another
- Provides connectivity and path selection between two end systems
- Routing
- IP Addresses and router
- IPv4 IPv6
- Also called logical address
Layer 4: Transport
- Handles packet sequencing, flow control and error detection
- Concerned with transportation issues between hosts
- Data transport reliability
- Establish, maintains and terminate virtual circuits
- Fault detection and recovery
- Information flow control
- TCP Protocol
Layer 5: Session
- Connections between applications
- Manages sessions
- provides maintenance on connections
- Remote call procedures (RPC)
- Simplex, half, full duplex communications
Layer 6: Presentation
- Presents data to the application and user in a comprehensible way
- Insures data is readable by receiving system
- Format of the data
- Negotiates data transfer syntax for application layer
- Concepts include data conversion
- JPEG, GIF, HTML
Layer 7: Application
-Where users interface with computer application
-Web browser, work processor, IM app
-Provides network services to application process such as email, file transfer
Protocol Telnet, FTP
TCP/IP Model
- Application Layer
- Transport Layer (Host To Host)
- Internet Layer
- Network Access
- created by US Defense Advanced Research Projects Agency in 1970s
- Suite of protocols including UDP, ICMP Layer 4
- IP Layer 3
TCP/IP Model OSI Model
TCP/ IP vs. OSI
Application Layer = Application Layer
Presentation Layer
Session Layer
Transport (Host To Host) Layer = Transport Layer
Internet Layer = Network Layer
Network Access = Data Link Layer
Physical Layer